Cap Stainless Steel Loop style for S/S water bottle Fits 12, 17, 20, 25 & 40 oz Loop cap in polypropylene fits all sizes of Klean Kanteen water bottles: 12 oz, 18 oz, 27 oz and 40 oz. Durable and lightweight. Clean in hot water with vinegar or mild soap. Loop cap can be attached to a caribiner and carried from a backpack